/**
 * MODERN FORMS CSS
 * Design système pour formulaires professionnels
 */

/* ============================================
   VARIABLES
   ============================================ */
:root {
  /* Couleurs principales */
  --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --success-color: #10b981;
  --error-color: #ef4444;
  --warning-color: #f59e0b;

  /* Couleurs neutres */
  --white: #ffffff;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;

  /* Border radius */
  --radius-sm: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms ease;
}

/* ============================================
   LAYOUT CONTAINERS
   ============================================ */
.form-container {
  max-width: 800px;
  width: 100%;
  margin: 0 auto;
  padding: var(--space-xl);
}

.form-card {
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: var(--radius-xl);
  padding: var(--space-2xl);
  box-shadow: var(--shadow-xl);
}

/* ============================================
   FORM GROUPS
   ============================================ */
.form-group {
  margin-bottom: var(--space-lg);
  position: relative;
}

.form-group:last-child {
  margin-bottom: 0;
}

.form-label {
  display: block;
  font-weight: 600;
  font-size: 0.875rem;
  margin-bottom: var(--space-sm);
  color: var(--white);
  letter-spacing: 0.025em;
}

.form-label .required {
  color: var(--error-color);
  font-weight: 700;
}

.form-label .optional {
  color: var(--gray-400);
  font-weight: 400;
  font-style: italic;
}

/* ============================================
   FORM INPUTS
   ============================================ */
.form-input,
.form-select,
.form-textarea {
  width: 100%;
  padding: 0.875rem 1.125rem;
  font-size: 0.9375rem;
  font-family: inherit;
  line-height: 1.5;
  color: var(--gray-900);
  background-color: rgba(255, 255, 255, 0.95);
  border: 2px solid transparent;
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
  appearance: none;
  box-sizing: border-box; /* FIX: Empêche les inputs de déborder */
}

.form-input::placeholder,
.form-textarea::placeholder {
  color: var(--gray-400);
}

/* États de focus */
.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  outline: none;
  background-color: var(--white);
  border-color: #667eea;
  box-shadow: 0 0 0 4px rgba(102, 126, 234, 0.1);
  color: var(--gray-900);
}

/* États de validation */
.form-input.valid,
.form-select.valid,
.form-textarea.valid {
  border-color: var(--success-color);
  padding-right: 2.5rem;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='%2310b981' viewBox='0 0 16 16'%3E%3Cpath d='M13.854 3.646a.5.5 0 0 1 0 .708l-7 7a.5.5 0 0 1-.708 0l-3.5-3.5a.5.5 0 1 1 .708-.708L6.5 10.293l6.646-6.647a.5.5 0 0 1 .708 0z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  background-size: 1rem;
}

.form-input.error,
.form-select.error,
.form-textarea.error {
  border-color: var(--error-color);
  padding-right: 2.5rem;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='%23ef4444' viewBox='0 0 16 16'%3E%3Cpath d='M16 8A8 8 0 1 1 0 8a8 8 0 0 1 16 0zM5.354 4.646a.5.5 0 1 0-.708.708L7.293 8l-2.647 2.646a.5.5 0 0 0 .708.708L8 8.707l2.646 2.647a.5.5 0 0 0 .708-.708L8.707 8l2.647-2.646a.5.5 0 0 0-.708-.708L8 7.293 5.354 4.646z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  background-size: 1rem;
}

/* État disabled */
.form-input:disabled,
.form-select:disabled,
.form-textarea:disabled {
  background-color: var(--gray-100);
  color: var(--gray-500);
  cursor: not-allowed;
  opacity: 0.6;
}

/* Textarea */
.form-textarea {
  min-height: 120px;
  resize: vertical;
}

/* Select */
.form-select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='%234b5563' viewBox='0 0 16 16'%3E%3Cpath d='M7.247 11.14 2.451 5.658C1.885 5.013 2.345 4 3.204 4h9.592a1 1 0 0 1 .753 1.659l-4.796 5.48a1 1 0 0 1-1.506 0z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  background-size: 1rem;
  padding-right: 2.5rem;
  cursor: pointer;
}

/* ============================================
   FORM ROWS & COLUMNS - SYSTÈME AMÉLIORÉ
   ============================================ */
.form-row {
  display: grid;
  grid-template-columns: repeat(2, 1fr); /* Défaut: 2 colonnes */
  gap: 15px;
  width: 100%; /* Assure que le conteneur ne déborde pas */
}

.form-row-2 {
  grid-template-columns: repeat(2, 1fr);
}

.form-row-3 {
  grid-template-columns: repeat(3, 1fr);
}

.form-row-4 {
  grid-template-columns: repeat(4, 1fr);
}

/* Responsive: Mobile = 1 colonne */
@media (max-width: 768px) {
  .form-row,
  .form-row-2,
  .form-row-3,
  .form-row-4 {
    grid-template-columns: 1fr;
  }
}

/* ============================================
   BUTTONS
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.875rem 1.5rem;
  font-size: 0.9375rem;
  font-weight: 600;
  line-height: 1.5;
  text-align: center;
  text-decoration: none;
  border: 2px solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-base);
  font-family: inherit;
  gap: var(--space-sm);
}

.btn:focus {
  outline: none;
  box-shadow: 0 0 0 4px rgba(102, 126, 234, 0.2);
}

.btn-primary {
  background: var(--primary-gradient);
  color: var(--white);
  border-color: transparent;
}

.btn-primary:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 10px 25px rgba(102, 126, 234, 0.3);
}

.btn-secondary {
  background: var(--white);
  color: #667eea;
  border-color: #667eea;
}

.btn-secondary:hover:not(:disabled) {
  background: #667eea;
  color: var(--white);
}

.btn-success {
  background: var(--success-color);
  color: var(--white);
}

.btn-danger {
  background: var(--error-color);
  color: var(--white);
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none !important;
}

.btn-block {
  width: 100%;
}

/* Loading state */
.btn.loading {
  position: relative;
  color: transparent;
}

.btn.loading::after {
  content: "";
  position: absolute;
  width: 1rem;
  height: 1rem;
  top: 50%;
  left: 50%;
  margin-left: -0.5rem;
  margin-top: -0.5rem;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-top-color: var(--white);
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* ============================================
   ALERTS & MESSAGES
   ============================================ */
.alert {
  padding: 1rem 1.25rem;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  margin-bottom: var(--space-lg);
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
}

.alert-success {
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.3);
  color: var(--success-color);
}

.alert-error {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.3);
  color: var(--error-color);
}

.alert-warning {
  background: rgba(245, 158, 11, 0.1);
  border: 1px solid rgba(245, 158, 11, 0.3);
  color: var(--warning-color);
}

.alert-info {
  background: rgba(59, 130, 246, 0.1);
  border: 1px solid rgba(59, 130, 246, 0.3);
  color: #3b82f6;
}

/* ============================================
   HELPER TEXT
   ============================================ */
.form-help {
  display: block;
  margin-top: var(--space-xs);
  font-size: 0.75rem;
  color: rgba(255, 255, 255, 0.7);
}

.form-error {
  display: block;
  margin-top: var(--space-xs);
  font-size: 0.75rem;
  color: var(--error-color);
  font-weight: 500;
}

/* ============================================
   FILE UPLOAD
   ============================================ */
.file-upload-wrapper {
  position: relative;
}

.file-upload-input {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

.file-upload-label {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem;
  background: rgba(255, 255, 255, 0.05);
  border: 2px dashed rgba(255, 255, 255, 0.3);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-base);
  color: rgba(255, 255, 255, 0.8);
  font-weight: 500;
}

.file-upload-label:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.5);
}

.file-upload-label.has-file {
  border-color: var(--success-color);
  background: rgba(16, 185, 129, 0.1);
}

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 640px) {
  .form-card {
    padding: var(--space-lg);
  }

  .form-container {
    padding: var(--space-md);
  }
}

/* ============================================
   ACCESSIBILITY
   ============================================ */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

/* Focus visible pour clavier */
*:focus-visible {
  outline: 2px solid #667eea;
  outline-offset: 2px;
}